A computer virus, much like a flu virus, is designed to spread from host to host and has the ability to replicate itself. Similarly, in the same way that flu viruses cannot reproduce without a host cell, computer viruses cannot reproduce and spread without programming such as a file or document.
In more technical terms, a computer virus is a type of malicious code or program written to alter the way a computer operates and is designed to spread from one computer to another. A virus operates by inserting or attaching itself to a legitimate program or document that supports macros in order to execute its code. In the process, a virus has the potential to cause unexpected or damaging effects, such as harming the system software by corrupting or destroying data.
How does a computer virus attack?
Once a virus has successfully attached to a program, file, or document, the virus will lie dormant until circumstances cause the computer or device to execute its code. In order for a virus to infect your computer, you have to run the infected program, which in turn causes the virus code to be executed.
This means that a virus can remain dormant on your computer, without showing major signs or symptoms. However, once the virus infects your computer, the virus can infect other computers on the same network. Stealing passwords or data, logging keystrokes, corrupting files, spamming your email contacts, and even taking over your machine are just some of the devastating and irritating things a virus can do.
While some viruses can be playful in intent and effect, others can have profound and damaging effects. This includes erasing data or causing permanent damage to your hard disk. Worse yet, some viruses are designed with financial gains in mind.
How do computer viruses spread?
In a constantly connected world, you can contract a computer virus in many ways, some more obvious than others. Viruses can be spread through email and text message attachments, Internet file downloads, and social media scam links. Your mobile devices and smartphones can become infected with mobile viruses through shady app downloads. Viruses can hide disguised as attachments of socially shareable content such as funny images, greeting cards, or audio and video files.
To avoid contact with a virus, it’s important to exercise caution when surfing the web, downloading files, and opening links or attachments. To help stay safe, never download text or email attachments that you’re not expecting, or files from websites you don’t trust.
What are the signs of a computer virus?
A computer virus attack can produce a variety of symptoms. Here are some of them:
- Frequent pop-up windows. Pop-ups might encourage you to visit unusual sites. Or they might prod you to download antivirus or other software programs.
- Changes to your homepage. Your usual homepage may change to another website, for instance. Plus, you may be unable to reset it.
- Mass emails being sent from your email account. A criminal may take control of your account or send emails in your name from another infected computer.
- Frequent crashes. A virus can inflict major damage on your hard drive. This may cause your device to freeze or crash. It may also prevent your device from coming back on.
- Unusually slow computer performance. A sudden change of processing speed could signal that your computer has a virus.
- Unknown programs that start up when you turn on your computer. You may become aware of the unfamiliar program when you start your computer. Or you might notice it by checking your computer’s list of active applications.
- Unusual activities like password changes. This could prevent you from logging into your computer.
How to help protect against computer viruses?
- Use a trusted antivirus product, such as Norton AntiVirus Basic, and keep it updated with the latest virus definitions. Norton Security Premium offers additional protection for even more devices, plus backup.
- Avoid clicking on any pop-up advertisements.
- Always scan your email attachments before opening them.
- Always scan the files that you download using file sharing programs.
What are the different types of computer viruses?
1. Boot sector virus
This type of virus can take control when you start — or boot — your computer. One way it can spread is by plugging an infected USB drive into your computer.
2. Web scripting virus
This type of virus exploits the code of web browsers and web pages. If you access such a web page, the virus can infect your computer.
3. Browser hijacker
This type of virus “hijacks” certain web browser functions, and you may be automatically directed to an unintended website.
4. Resident virus
This is a general term for any virus that inserts itself in a computer system’s memory. A resident virus can execute anytime when an operating system loads.
5. Direct action virus
This type of virus comes into action when you execute a file containing a virus. Otherwise, it remains dormant.
6. Polymorphic virus
A polymorphic virus changes its code each time an infected file is executed. It does this to evade antivirus programs.
7. File infector virus
This common virus inserts malicious code into executable files — files used to perform certain functions or operations on a system.
8. Multipartite virus
This kind of virus infects and spreads in multiple ways. It can infect both program files and system sectors.
9. Macro virus
Macro viruses are written in the same macro language used for software applications. Such viruses spread when you open an infected document, often through email attachments.
How to clear cookies in Chrome, Firefox, Safari, and other browsers
If you surf the web, computer cookies can be useful because they keep track of items in your shopping carts and save your personal information — including login credentials — so sites can remember you and what your preferences are. They can make online transactions extremely convenient, as you don’t have to enter in your information every time you visit a site. Instead, logging into your favorite websites is quick and easy.
However, cookies can pose a privacy risk due to the amount of information they can hold. Cookies record your personally identifiable information so they can help auto-fill forms on browsers. This information may include your name, address, account login credentials, and more. If you prefer to protect your privacy when it comes to cookies, you may want to delete them. But keep in mind, if you choose this method you will lose the convenience of stored passwords and other data.
This article provides current step-by-step instructions on how to clear cookies from the latest versions of five popular web browsers, as of June 2018.
Chrome: how to delete cookies in Chrome on your Windows or Mac computer
- Open Chrome.
- In the top right corner of the browser you will see three dots, which indicates a settings menu.
- Scroll down to the bottom of the page and click on “Advanced.”
- Click on the section “Clear browsing data.”
- Under the “All cookies and site data” section, you can customize which cookies to delete based on a specific time range and other options. Finally, you can complete the deletion by clicking “Clear data.” You can also clear your cache, which is where your computer stores previously viewed websites so they can be loaded faster on future visits.
Chrome: how to delete cookies in Chrome on your Android device
- On your Android phone or tablet, open the Chrome app.
- To the right of the address bar, tap on “More,” or what looks like three dots, and then select “Settings.”
- Tap on the “Privacy” category and then select “Clear browsing data.”
- Here you can personalize your selections for which cookies to delete by selecting a specific time range.
5. Once you have made your selections, you can then check “Cookies and site data.” Uncheck all the other items.
6. Tap “Clear data.”
Chrome: how to delete cookies in Chrome on your iOS device
- On your device, launch the Chrome app.
- At the top right, tap on the three dots, scroll down and then select “Settings.”
- Under settings, tap “Privacy” then “Clear browsing data.”
- Select “Cookies, site data,” and uncheck all other items.
5. Tap on “Clear browsing data.”
6. Then select “Done.
Firefox :how to delete cookies in Firefox on your Windows or Mac computer:
- Open Firefox on your computer.
- In the upper right-hand corner of the browser, click the “menu bars,” which look like three parallel lines, and click the “Privacy” tab.
- Here you can select “Clear your recent history.”
- Be sure that only “Cookies” is checked, and then select the time frame for which you would like to delete your cookies. If you want to delete all cookies, select “Everything.”
5. Double check your selections to make sure that other items you want to keep are not selected, and then hit “Clear now.”
Some instructions may vary based on the type of phone you have and what version of Firefox it is running. Look for the menu icon (three bars) located at the top right corner. On older Android devices you’ll have to press the hardware menu key and then tap “More.”
- Go to the “Settings” menu.
- On the settings menu, look for “Privacy & security” and select “Clear private data.”
- You will then be taken to a list of what can be cleared where you can select “Cookies & active logins.”
- After you have made your selection, tap the “Clear data” button to finalize deleting cookies.
- Open Firefox.
- Click on the “menu bars,” which looks like three parallel lines in the lower right-hand corner of the browser window.
- Select “Settings.”
- Scroll down to “Privacy.”
- Select “Clear private data.”
- Make sure only “Cookies” is selected, then tap on “Clear private data.”
- Open Safari.
- Select “Preferences” from the dropdown Safari menu.
- Click on “Privacy,” then on “Manage Website Data.”
- Click on “Remove all” from the dropdown menu.
- Go into the Settings menu on your device.
- Scroll down to “Safari,” then “Advanced,” then “Website Data”
- Tap on “Clear history and website data” to clear cookies.
Internet Explorer: how to delete cookies in Internet Explorer for Windows 10, Windows 8.1, and Windows 7 on your Windows PC
- Launch Internet Explorer.
- Select “Tools” from the menu, select the “Safety” menu, and then select “Delete browsing history.”
3. Make sure that the “Cookies and website data” checkbox is selected, and then click on “Delete.”
- Launch Microsoft Edge and go to the “more” menu and select “Settings.”
- Scroll to “Clear browsing data,” and then select “cookies and saved website data” and then select clear.
There are a few different reasons why you would want to clear your browser’s cookies. Whether for privacy reasons or general computer maintenance and clean up, most browsers make clearing your cookies a fairly easy task.
Alternatively, if you don’t want to clear your cookies because you appreciate the convenience of not having to constantly log in to your favorite sites, be sure to invest in a reputable VPN such as Norton WiFi Privacy to protect your sensitive information. Norton WiFi Privacy not only encrypts the data being sent to and from your computer, but it also blocks ad trackers by intercepting cookies and removing your personally identifiable information.